Here are just a few sketches from our walk along. I am using Paper 53, because I decided that I really liked its limitations .... Other sketch Apps I used were either too clunky to manipulate, made lines that all looked the same, or took too much time to master as tools. Paper has serious limitations, such as the color palette, but I love the lines it makes. Yes, as an app, it is a bit pricey, $7.99, but I figure that is about the cost of one pad of paper!
And, one thing I learned from Lisa Call, setting limitations as rules can be a good thing.